Devices in a network that are required to have synchronized clocks can use timing synchronization protocols to synchronize with each other. One example of such a protocol is the Precision Time Protocol (PTP). PTP uses a master-slave architecture for clock distribution. A PTP master is a device with one or more clocks with which other devices, referred to as PTP slaves, synchronize. A PTP master causes a PTP slave to synchronize the slave's local clock to the clock of the master by periodically sending a synchronization message to the slaves over the data communications network.
To test the quality of the slave systems in synchronizing the local clocks of the slave (device under test) with the clock of the master (the test device), some slave systems provide a separate physical interface to output a test signal, e.g., a one pulse per second (PPS) output or a 10 MHz output. However, requiring a separate interface for testing recovered clock quality is undesirable in some applications, such as automobile electronic control units, where production costs or the operating environment makes a separate physical test interface infeasible.
Another problem associated with testing recovered clock quality is that the network messages used to test recovered quality may be layer two messages that are not mutable over a layer two network. As a result, testing can only be performed on a point-to-point basis and results from every point need to be stored. When a network includes one or more boundary clocks between a master and a slave, a single test system that is only connected to one of the boundary clocks may not be capable of testing the recovered clock quality of the remaining boundary clocks and the slave.
Accordingly, there exists a need for improved methods, systems, and computer readable media for testing recovered clock quality.